reset.c

   1 #include "git-compat-util.h"
   2 #include "cache-tree.h"
   3 #include "lockfile.h"
   4 #include "refs.h"
   5 #include "reset.h"
   6 #include "run-command.h"
   7 #include "tree-walk.h"
   8 #include "tree.h"
   9 #include "unpack-trees.h"
  10 #include "hook.h"
  11
  12 static int update_refs(const struct reset_head_opts *opts,
  13                        const struct object_id *oid,
  14                        const struct object_id *head)
  15 {
  16         unsigned detach_head = opts->flags & RESET_HEAD_DETACH;
  17         unsigned run_hook = opts->flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
  18         unsigned update_orig_head = opts->flags & RESET_ORIG_HEAD;
  19         const struct object_id *orig_head = opts->orig_head;
  20         const char *switch_to_branch = opts->branch;
  21         const char *reflog_branch = opts->branch_msg;
  22         const char *reflog_head = opts->head_msg;
  23         const char *reflog_orig_head = opts->orig_head_msg;
  24         const char *default_reflog_action = opts->default_reflog_action;
  25         struct object_id *old_orig = NULL, oid_old_orig;
  26         struct strbuf msg = STRBUF_INIT;
  27         const char *reflog_action;
  28         size_t prefix_len;
  29         int ret;
  30
  31         if ((update_orig_head && !reflog_orig_head) || !reflog_head) {
  32                 if (!default_reflog_action)
  33                         BUG("default_reflog_action must be given when reflog messages are omitted");
  34                 reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
  35                 strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action :
  36                                                           default_reflog_action);
  37         }
  38         prefix_len = msg.len;
  39
  40         if (update_orig_head) {
  41                 if (!get_oid("ORIG_HEAD", &oid_old_orig))
  42                         old_orig = &oid_old_orig;
  43                 if (head) {
  44                         if (!reflog_orig_head) {
  45                                 strbuf_addstr(&msg, "updating ORIG_HEAD");
  46                                 reflog_orig_head = msg.buf;
  47                         }
  48                         update_ref(reflog_orig_head, "ORIG_HEAD",
  49                                    orig_head ? orig_head : head,
  50                                    old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
  51                 } else if (old_orig)
  52                         delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
  53         }
  54
  55         if (!reflog_head) {
  56                 strbuf_setlen(&msg, prefix_len);
  57                 strbuf_addstr(&msg, "updating HEAD");
  58                 reflog_head = msg.buf;
  59         }
  60         if (!switch_to_branch)
  61                 ret = update_ref(reflog_head, "HEAD", oid, head,
  62                                  detach_head ? REF_NO_DEREF : 0,
  63                                  UPDATE_REFS_MSG_ON_ERR);
  64         else {
  65                 ret = update_ref(reflog_branch ? reflog_branch : reflog_head,
  66                                  switch_to_branch, oid, NULL, 0,
  67                                  UPDATE_REFS_MSG_ON_ERR);
  68                 if (!ret)
  69                         ret = create_symref("HEAD", switch_to_branch,
  70                                             reflog_head);
  71         }
  72         if (!ret && run_hook)
  73                 run_hooks_l("post-checkout",
  74                             oid_to_hex(head ? head : null_oid()),
  75                             oid_to_hex(oid), "1", NULL);
  76         strbuf_release(&msg);
  77         return ret;
  78 }
  79
  80 int reset_head(struct repository *r, const struct reset_head_opts *opts)
  81 {
  82         const struct object_id *oid = opts->oid;
  83         const char *switch_to_branch = opts->branch;
  84         unsigned reset_hard = opts->flags & RESET_HEAD_HARD;
  85         unsigned refs_only = opts->flags & RESET_HEAD_REFS_ONLY;
  86         unsigned update_orig_head = opts->flags & RESET_ORIG_HEAD;
  87         struct object_id *head = NULL, head_oid;
  88         struct tree_desc desc[2] = { { NULL }, { NULL } };
  89         struct lock_file lock = LOCK_INIT;
  90         struct unpack_trees_options unpack_tree_opts = { 0 };
  91         struct tree *tree;
  92         const char *action;
  93         int ret = 0, nr = 0;
  94
  95         if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
  96                 BUG("Not a fully qualified branch: '%s'", switch_to_branch);
  97
  98         if (opts->orig_head_msg && !update_orig_head)
  99                 BUG("ORIG_HEAD reflog message given without updating ORIG_HEAD");
 100
 101         if (opts->branch_msg && !opts->branch)
 102                 BUG("branch reflog message given without a branch");
 103
 104         if (!refs_only && repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0) {
 105                 ret = -1;
 106                 goto leave_reset_head;
 107         }
 108
 109         if (!get_oid("HEAD", &head_oid)) {
 110                 head = &head_oid;
 111         } else if (!oid || !reset_hard) {
 112                 ret = error(_("could not determine HEAD revision"));
 113                 goto leave_reset_head;
 114         }
 115
 116         if (!oid)
 117                 oid = &head_oid;
 118
 119         if (refs_only)
 120                 return update_refs(opts, oid, head);
 121
 122         action = reset_hard ? "reset" : "checkout";
 123         setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 124         unpack_tree_opts.head_idx = 1;
 125         unpack_tree_opts.src_index = r->index;
 126         unpack_tree_opts.dst_index = r->index;
 127         unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 128         unpack_tree_opts.update = 1;
 129         unpack_tree_opts.merge = 1;
 130         unpack_tree_opts.preserve_ignored = 0; /* FIXME: !overwrite_ignore */
 131         unpack_tree_opts.skip_cache_tree_update = 1;
 132         init_checkout_metadata(&unpack_tree_opts.meta, switch_to_branch, oid, NULL);
 133         if (reset_hard)
 134                 unpack_tree_opts.reset = UNPACK_RESET_PROTECT_UNTRACKED;
 135
 136         if (repo_read_index_unmerged(r) < 0) {
 137                 ret = error(_("could not read index"));
 138                 goto leave_reset_head;
 139         }
 140
 141         if (!reset_hard && !fill_tree_descriptor(r, &desc[nr++], &head_oid)) {
 142                 ret = error(_("failed to find tree of %s"),
 143                             oid_to_hex(&head_oid));
 144                 goto leave_reset_head;
 145         }
 146
 147         if (!fill_tree_descriptor(r, &desc[nr++], oid)) {
 148                 ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 149                 goto leave_reset_head;
 150         }
 151
 152         if (unpack_trees(nr, desc, &unpack_tree_opts)) {
 153                 ret = -1;
 154                 goto leave_reset_head;
 155         }
 156
 157         tree = parse_tree_indirect(oid);
 158         prime_cache_tree(r, r->index, tree);
 159
 160         if (write_locked_index(r->index, &lock, COMMIT_LOCK) < 0) {
 161                 ret = error(_("could not write index"));
 162                 goto leave_reset_head;
 163         }
 164
 165         if (oid != &head_oid || update_orig_head || switch_to_branch)
 166                 ret = update_refs(opts, oid, head);
 167
 168 leave_reset_head:
 169         rollback_lock_file(&lock);
 170         clear_unpack_trees_porcelain(&unpack_tree_opts);
 171         while (nr)
 172                 free((void *)desc[--nr].buffer);
 173         return ret;
 174
 175 }